Center surround detection explained?

A while back I asked about human vision processing and if it is performed synchronously or asynchronously. One of the responses mentioned that the retina performs 'Center Surround Detection'. So I tried to google what this is but no relevant results came up.

Is anyone able to explain what this is and how its useful or point me to a link that explains it (that is not too high level/hard to understand)?

Here is a wikipedia link I found googling center surround. Go to the retinal ganglion cells section.
The same search page showed links to several youtube videos on the subject.

Within the retina, a ganglion cell will be activated when the photorecptors it receives inputs from are activated if they are in the center area of the receptive field. Activation of photoreceptor in the surround area of the receptive field will inhibit the retinal ganglion cell (RGC).
This makes a sharper response to small areas of illumination. A linear array of these center surround receptive fields will then be able to activate higher order cells (getting RGC inputs) which will act as line detectors.